Guernsey Police is appealing for witnesses to the incident, which happened at around 01:00 on Sunday morning.
“A man suffered significant facial injury after being punched,” confirmed Guernsey Police.
“A male, 18, has been arrested on suspicion of grievous bodily harm. He has been released on bail pending further enquiries.”
Anyone who witnessed the incident is asked to contact T/DC 85 De La Mare on 725111.